Enabling a list view to be a lookup target

For security purposes, list views in custom Lists tools are initially disabled as targets for lookups from other tools. Note that in addition to enabling a selected list view to be a lookup target, the tool designer must also enable the tool be a lookup target.

Open the Designer.

Click the view you want to enable as a lookup target.

Click the Properties tab.

Check Allow this view to provide data to lookups defined in this workspace.